In hydraulic mountings such as that disclosed in European Patent 0 040 290, the length of the ring channel in the nozzle body can be altered before the nozzle is assembled by twisting the stop plates with respect to one another. In this way, the damping characteristics of the hydraulic mounting containing the nozzle body can be adjusted. To ensure that no air bubbles are incorporated into the hydraulic mounting that could affect the damping properties, the mounting is normally assembled while submersed in a tank of hydraulic fluid. And this presents problems of handling and fluid (gas) exposure.